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  1. Yup, Prentice's rule is not dead-on balls...

    Yup, Prentice's rule is not dead-on balls accurate for oblique angles of view, and certainly doesn't take into account higher orders of aberration (3rd?), just as best form theory breaks down over...
  2. Brent, The formulas I've seen make no mention...

    Brent,

    The formulas I've seen make no mention of thickness, but then at our level (ophthalmic dispensing) .01∆ of Transverse Chromatic Aberration is, practically speaking, inconsequential...
  3. I'm not aware of any direct correlation between...

    I'm not aware of any direct correlation between thickness and dispersion, at least with ophthalmic lenses.

    Generally, higher refractive index lenses have greater levels of dispersion.

    Perhaps...
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    It's a Beautiful Day - White Bird 1970 Escape...

    It's a Beautiful Day - White Bird 1970

    Escape from doomscrolling and apocalypse prepping. Heroin optional.

    ...
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    Destructive interference. Where does the...

    Destructive interference. Where does the cancelled energy go? Through the lens, increasing light transmission, satisfying the conservation of energy law.
    ...
  6. My books are at the office, so from memory: ...

    My books are at the office, so from memory:

    1) Our eyes/orbits are angled down slightly, maybe so that our ancestors didn't walk over cliffs!
    2) We tend to lower our gaze when focusing on near...
  7. Here's the white paper referenced in the above...

    Here's the white paper referenced in the above link.

    https://www.zeiss.co.uk/content/dam/Vision%20Care/Vision/en_us/PDF/ECP/ZEISS_Individual_SV_White_Paper_15630.pdf
  8. Your welcome. I like the familylike atmosphere...

    Your welcome. I like the familylike atmosphere here.

    See:...
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    Juno, I've seen coatings build up and 'run' at...

    Juno, I've seen coatings build up and 'run' at the segments that would match the symptoms- pretty easy to see when held up to the light. However, it's not that common with the better coating systems,...
  10. Yes sonny, you are absolutely correct, except for...

    Yes sonny, you are absolutely correct, except for the bold part where the relationship is .5mm per 1˚ of pantoscopic tilt.

    I do get some relatively simple PAL Rxs on occasion. When their POW...
  11. No direct relationship because the software (when...

    No direct relationship because the software (when POW capable) corrects for any misalignment of the lens and visual optical axes. The 4mm 'drop' reduces lens thickness by aligning the PRP closer to...
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    Yup, as written, there is insufficient data. Most...

    Yup, as written, there is insufficient data. Most folks have two eyes, with two corrective lenses. We're forced to assume both eyes have the same power in the 180 meridian. Punt.

    Adrianna, did...
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    Elvin Bishop - Struttin' My Stuff 1974 ...

    Elvin Bishop - Struttin' My Stuff 1974


    https://www.youtube.com/watch?v=mMNSsGzdjs0
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    Invisible Spectacles

    Earliest example (1939) of cosmetic contact lens use in cinema? LeVar Burton would be impressed.

    https://rommerreviewsdotcom.wordpress.com/2016/07/06/miracles-for-sale-1939-two-and-half-stars/
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    Procol Harum – A Whiter Shade of Pale 1968 I...

    Procol Harum – A Whiter Shade of Pale 1968

    I viewed Scorsese's 'Life Lessons' yesterday, where he used AWSOP for the intro, outro, and once or twice in the middle. Check it out.
    ...
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    Kraftwerk - The Robots 1978 ...

    Kraftwerk - The Robots 1978


    https://www.youtube.com/watch?v=As-iBOqACms
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    Salem Travelers - Tell It Like It Is 1969 ...

    Salem Travelers - Tell It Like It Is 1969


    https://www.youtube.com/watch?v=jOTDOGD66oQ
  18. Replies
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    Malcom Kogut - Addams Family 2012 ...

    Malcom Kogut - Addams Family 2012


    https://www.youtube.com/watch?v=218Mw7kWI_g

    Finally, a live recording of the theme song to The Addams Family played on a pipe organ, specifically, a...
  19. The risk of eye infection when using home brew or...

    The risk of eye infection when using home brew or non-sterile (and not filtered, preserved etc.) eye drops is not insignificant.

    https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3586833/

    Best...
  20. Welcome to OB. Adding to Mervinek's...

    Welcome to OB.

    Adding to Mervinek's discussion,

    Prisms can also be cemented onto the lenses, sometimes for when the deviation varies depending on the angle of gaze, typically the primary and...
  21. Drk, I see what you're getting at, that wider...

    Drk,

    I see what you're getting at, that wider PDs converge more than narrower PDs, where a 75mm PD will converge 2.25mm @40cm/eye, and a 55mm PD will converge 1.65mm/eye, and can't be accounted...
  22. Many people are saying that this anti-bacterial...

    Many people are saying that this anti-bacterial coating might also reduce acne, scars, cellulite, and stretch marks.*

    *I have acquaintances who either work for VSP or own their stock. One of...
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    Roy Orbison - Blue Bayou 1988 ...

    Roy Orbison - Blue Bayou 1988


    https://www.youtube.com/watch?v=r1EjTX3X3pc

    https://en.wikipedia.org/wiki/Roy_Orbison_and_Friends:_A_Black_and_White_Night
  24. Drk, If the mono distance pd is 34/30, then...

    Drk,

    If the mono distance pd is 34/30, then the near inset would be 1.5mm in per eye for 32.5/28.5, and would be true for even "dumb" PALs. Moreover, some archaic semifinished PALs would vary the...
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    Supertramp - The Logical Song 1979 ...

    Supertramp - The Logical Song 1979


    https://www.youtube.com/watch?v=11afPoEkJL8
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